Monoazo dyestuffs



MoNoAZo DYESTUFFS Ernst Merian, Allschwil, near Basel, Switzerland,assignor,

by mesne assignments, to Saul & Co., Newark, N. J., as nominee ofFidelity Union Trust Company No Drawing. Application April 20, 1953,Serial No. 349,983

Claims priority, application Switzerland April 22, 1952 6 Claims. (Cl.260-2071) I R: R:

wherein each of R1 and R2 stands for lower alkyl, lower hydroxyalkyl orlower alkoxyalkyl, and R3 stands for hydrogen, halogen, lower alkyl orlower alkoXy.

The dyeings of these new dyestuffs on acetate silk are greatly superiorwith respect to fastness to light as compared to those of correspondingdyestuffs containing no cyanoalkyl group. Moreover they arecharacterized by outstanding fastness with respect to so-called gasfumes. Surprisingly the dyeings are also much faster to light and gasfumes than those of corresponding dyestuffs containing no carboxylicester group. The dyeings of these dyestuffs on synthetic polyamidefibers and on polyester fibers too are improved in a similar way withrespect to fastness properties though not in the same size. An object ofthe present invention is thus the improvement of the fastness propertiesof acetate dyes comprising an azo component of the series of tertiaryamines. This is accomplished according to the present invention by theintroduction of both acyanoalkyl group into the azo component and acarboxylic ester grou into the nucleus of the diazo component.

The said monoazo dyestuffs can be prepared by coupling 1 mol of thediazo compound of a 2-amino-5-nitrobenzene-l-carboxylic acid derivativeof the formula wherein R1 stands for lower alkyl, lower hydroxyalkyl orlower alkoxyalkyl, with 1 mol of a tertiary amine of the formulaCHr-CHf-CN 3 R3 wherein R2 stands for lower alkyl, lower hydroxyalkyl orlower alkoxyalkyl, and R3 stands for hydrogen, halogen, lower alkyl orlower alkoxy.

Lower alkyl throughout the specification stands for methyl, ethyl,propyl or butyl, whereas halogen means chlorine or bromine.

Illustrative of amines which may be employed in prenited States Patentfor example N-methyl N cyanoethyl-aminobenzene, N-'

ethyl N cyanoethyl aminobenzene, Nhydroxyethyl-N-cyanoethyl-aminobenzene, N-hydroxypropy1N-cyanoethyl-aminobenzene, N-hydroXybutyl-N-cyanoethyl- 'aminobenzene, NmethoXyethyl-N-cyanoethyl-aminobcnzene, 1 a (N methyl N cyanoethyl)amino 3- methylbenzene, l-(N-ethyl-N-cyanoethyl)-amino-3-methylbenzene,1 Q (N hydroxyethyl N cyanoethyl)- amino-3-methylben-zene, 1-(N-hydroxypropyleN cyanoethyl) amino 3' methylbenzene, 1 (N methyl N-cyanoethyl) amino 3' chlorobenze'ne, 1 (N ethyl- N cyanoethyl) amino 3chlorobenzene, 1 (N- hydroxyethyl N cyanoethyl) amino 3 chlorobenzene, 1(N methyl N cyanoethyl) amino 3- bromobenzene, 1 (N ethyl N cyanoethyl)amino- 3 bromobenzene, l (N hydroxyethyl-N-cyanoethyl)- amino 3bromobenzene, l (N hydroxyethyl N- cyanoethyl)-arnino-3-methoxybenzene,1-(N-hydroxyethyl-N-cyanoethy'l)-amino-3-ethoxybenzene,l-(N-hydroxyethyl-N-cyanoethyl)-amino-3-ethylbenzene, etc.

The following examples illustrate the invention without, however, beingrestrictive thereof. In the said examples the parts and percentages areby weight, and the temperatures are in degrees centigrade.

Example I 5 parts of sodium nitrite are added to 60 parts ofconcentrated sulfuric acid at 60 in the course of 1 hour. The solutionis cooled to 1020 and then diluted with 65 parts of concentrated aceticacid, whereupon 13 parts of 2-amino-5-nitrobenzene-l-carboxylic acidmethyl ester are added at 1015. Then 65 parts of concentrated aceticacid are added dropwise, and the excess of nitrite destroyed by means of2 parts of urea. The diaz o solution is poured onto 750 parts of ice,and the coupling is carried out with a solution of 14 parts of 1-(N-hydroxyethyl-N-cyanoethyl)-amino-3-methylbenzene in parts of water, 70parts of ice and 16 parts of 30% hydrochloric acid. The formed dyestutfseparates soon in form of dark red needles. It is filtered off, washedfree of acid and dried. It corresponds to the formula CO-O-CHsCHE-CHQ-CN and dyes acetate silk in scarlet shades of outstandingfastness properties. The new dyestutf is twice as fast tolight, fourtimes as fast to gas fumes and much faster to washing than thecorresponding dyestuff of the formula which contains no carboxylic estergroup. Polyamide fibers, known under the name of nylon or Perlon aredyed in somewhat bluisher shades of good fastness properties, while thescarlet dyeings on polyester fibers,

Patented Feb. 19, 1957' known for instance under the name of Dacron,have excellent fastness to light.

Example 2 20 parts of Z-amino-S-nitrobenzene-l-carboxylic acid methylester are dissolved in 100 parts of concentrated sulfuric acid. Thesolution is poured onto 300 parts of ice. The yellowish suspension soobtained is filtered off, washed free from acid and, without drying,stirred up in 60 parts of 30% hydrochloric acid. After some time 7 partsof sodium nitrite are added, whereupon coupling is carried out with asolution of 16 parts of N-methyl-N-cyanoethyl-aminobenzene in 230 partsof water, 21 parts of 30% hydrochloric acid and 200 parts of ice. Afterisolation in the usual way, a dyestutf melting at 136 is obtained, whichcorresponds to the following formula CO-O-CHs It dyes acetate silk inreddish orange shades of outstanding fastness to light and gas fumes.The dyeings on polyester fibers are brilliant scarlet in shade andpossess very good fastness properties.

Dyestufis of similar properties as those described in the presentexample and obtainable in analogous manner are the following ones:

CHr-CHz-CN CH:- CH:

and melting at 163 is obtained, which dyes acetate silk in scarletshades possessing outstanding fastness properties.

Example 4 25 parts of Z-amino-S-nitrobenzene-l-carboxylic acidethoxyethyl ester are diazotized as described in Example 2, whilecoupling is carried out with a solution of 19 parts ofN-hydroxyethyl-N-cyanoethyl-aminobenzene in 2000 parts of water, 25parts of 30% hydrochloric acid and 200 parts of ice. A reddish orangeacetate dyestutf is obtained which corresponds to the formula Dyestuffsof similar properties as those described in the present example andobtainable in analogous manner are the following ones:

CO-O-CHi-CHs-O-CzHg CHrCHrO-CHg-CH:

CHr-CHz-CN CH;--GH:OH

Example 5 20 parts of Z-amino-S-nitrobenzene-l-carboxylic acid methylester are diazotized as described in Example 2, while coupling iscarried outwith a solution of 19 parts of N hydroxyethyl N cyanoethylaminobenzene in 2000 parts of water, 25 parts of 30% hydrochloric acidand 200 parts of ice. The dyestutf thus obtained corresponds to theformula and dyes acetate silk and polyester fibers in brilliant red dishorange shades of outstanding fastness properties, the shades onpolyamide fibers being somewhat redder in tone.

CHz-CHr-CN Example 6 CHz-CHr-OH respectively p C OO--CHz-CH2OHCHz-CHr-OH Example 7 23 parts of 2-amino-5-nitrobenzene-1-carboxylicacid are dissolved in 100 parts of concentrated sulfuric acid, whereupon25 parts of methanol are added drop by drop. The temperature is raisedup to 80 and after some time esterification is finished. Withoutisolation of the intermediate product, 9 par-ts of sodium nitrite arenow added in small portions at 60 to the well agitated mass which isheld at 6070 for one further hour. Then it is poured onto 1500 parts ofWater and 500 parts of ice. At about a solution of 23 parts ofl-(N-hydroxyethyl N-cyanoethyl)-3-methylbenzene in 31 parts of 30%hydrochloric acid and 50 parts of water is added and the couplingcarried out in the usual manner. After some time the dyestuffprecipitates and is isolated in the usual way. It is identical with thedyestutf of Example 1.

Example 8 1.5 parts of the dyestuff according to Example 1 is dispersedwith the aid of Turkey red oil, and the resultant dispersion used fordyeing 100 parts of acetate silk in a soap bath in the conventional Way,preferably at elevated temperature. Pure scarlet shades of excellentfastness properties are obtained. To enhance the dispersion, thedyestuff may be ground, prior to the dyeing process, with a wettingagent, dispersing agent or emulsifier, preferably in the presence of aninorganic salt such as sodium sulfate.

In a similar manner synthetic polyamid fibers and polyester fibers maybe dyed, whereby the temperature is preferably raised up to the boil oreven higher, it closed vessels are used; the shades dilfering only to asmall extent.

Having thus disclosed the invention, what is claimed is: Y

1. A monoazo dyestutf which corresponds to the formula COOCH2X whereineach X stands for a member selected from the group consisting ofhydrogen and methyl, and wherein Y stands for a member selected from thegroup consisting of hydrogen, methyl, hydroxymethyl, hydroxyethyl and 5hydroxypropyl.

2. The monoazo dyestutf which corresponds to the formula 3. The monoazodyestuff which corresponds to the formula I oo-o-om C 112- CH:

4. The monoazo dyestutf which corresponds to the formula oral-011F011 5.The monoazo dyestuff which corresponds to the formula C Hr CH2- 0 H 6.The monoazo dyestuff which corresponds to the formula 1 c0o02H 1/OHaCHa-CN CH -CH OH 40 (3H3 References Cited in the file of this patentUNITED STATES PATENTS 2,135,008 Kleiner et al. Nov. 1, 1938 2,387,987Felix Oct. 30, 1945 2,492,971 Dickey Jan. 3, 1950

1. A MONAZO DYESTUFF WHICH CORRESPONDS TO THE FORMULA